Power management system for active stylus

ABSTRACT

In one embodiment, a stylus includes one or more electrodes and one or more computer-readable non-transitory storage media embodying first logic for transmitting signals wirelessly to a device through a touch-sensor of the device. The stylus has a first power mode in which components of the stylus for receiving signals from or transmitting signals to the device are powered off; a second power mode in which components of the stylus for receiving signals from the device are powered on at least periodically and components of the stylus for transmitting signals to the device are powered off; and a third power mode in which components of the stylus for transmitting signals to the device are powered on at least periodically. The media further embodies second logic for transitioning the stylus from one of the first, second, and third power modes to another one of the first, second, and third power modes.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit, under 35 U.S.C. § 119(e), of U.S.patent application Ser. No. 16/207,903, filed Dec. 3, 2018, now U.S.Pat. No. 10,579,120, issued Mar. 3, 2020, which is a continuation ofU.S. patent application Ser. No. 13/329,270, filed Dec. 17, 2011, nowU.S. Pat. No. 10,162,400, issued Dec. 25, 2018, which claims the benefitof Provisional Patent Application No. 61/553,114, filed Oct. 28, 2011,which is incorporated herein by reference.

BACKGROUND Technical Field

This disclosure generally relates to active styluses.

Description of the Related Art

A touch sensor may detect the presence and location of a touch or theproximity of an object (such as a user's finger or a stylus) within atouch-sensitive area of the touch sensor overlaid on a display screen,for example. In a touch-sensitive-display application, the touch sensormay enable a user to interact directly with what is displayed on thescreen, rather than indirectly with a mouse or touch pad. A touch sensormay be attached to or provided as part of a desktop computer, laptopcomputer, tablet computer, personal digital assistant (PDA), smartphone,satellite navigation device, portable media player, portable gameconsole, kiosk computer, point-of-sale device, or other suitable device.A control panel on a household or other appliance may include a touchsensor.

There are a number of different types of touch sensors, such as, forexample, resistive touch screens, surface acoustic wave touch screens,and capacitive touch screens. Herein, reference to a touch sensor mayencompass a touch screen, and vice versa, where appropriate. When anobject touches or comes within proximity of the surface of thecapacitive touch screen, a change in capacitance may occur within thetouch screen at the location of the touch or proximity. A touch-sensorcontroller may process the change in capacitance to determine itsposition on the touch screen.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates an example touch sensor with an example touch-sensorcontroller.

FIG. 2 illustrates an example active stylus exterior.

FIG. 3 illustrates an example active stylus interior.

FIG. 4 illustrates an example active stylus with touch sensor device.

FIG. 5 illustrates example power management systems and power sourcesfor an active stylus and touch-sensitive device.

FIG. 6 illustrates an example set of power modes for an active stylusand the methods of transitioning between them.

FIG. 7 illustrates an example method for powering an active stylus in avariety of power modes.

FIG. 8 illustrates an example of duty cycling a component in aparticular power mode.

DETAILED DESCRIPTION

FIG. 1 illustrates an example touch sensor 10 with an exampletouch-sensor controller 12. Touch sensor 10 and touch-sensor controller12 may detect the presence and location of a touch or the proximity ofan object within a touch-sensitive area of touch sensor 10. Herein,reference to a touch sensor may encompass both the touch sensor and itstouch-sensor controller, where appropriate. Similarly, reference to atouch-sensor controller may encompass both the touch-sensor controllerand its touch sensor, where appropriate. Touch sensor 10 may include oneor more touch-sensitive areas, where appropriate. Touch sensor 10 mayinclude an array of drive and sense electrodes (or an array ofelectrodes of a single type) disposed on one or more substrates, whichmay be made of a dielectric material. Herein, reference to a touchsensor may encompass both the electrodes of the touch sensor and thesubstrate(s) that they are disposed on, where appropriate.Alternatively, where appropriate, reference to a touch sensor mayencompass the electrodes of the touch sensor, but not the substrate(s)that they are disposed on.

An electrode (whether a ground electrode, guard electrode, driveelectrode, or sense electrode) may be an area of conductive materialforming a shape, such as for example a disc, square, rectangle, thinline, other suitable shape, or suitable combination of these. One ormore cuts in one or more layers of conductive material may (at least inpart) create the shape of an electrode, and the area of the shape may(at least in part) be bounded by those cuts. In particular embodiments,the conductive material of an electrode may occupy approximately 100% ofthe area of its shape. As an example and not by way of limitation, anelectrode may be made of indium tin oxide (ITO) and the ITO of theelectrode may occupy approximately 100% of the area of its shape(sometimes referred to as a 100% fill), where appropriate. In particularembodiments, the conductive material of an electrode may occupysubstantially less than 100% of the area of its shape. As an example andnot by way of limitation, an electrode may be made of fine lines ofmetal or other conductive material (FLM), such as for example copper,silver, or a copper- or silver-based material, and the fine lines ofconductive material may occupy approximately 5% of the area of its shapein a hatched, mesh, or other suitable pattern. Herein, reference to FLMencompasses such material, where appropriate. Although this disclosuredescribes or illustrates particular electrodes made of particularconductive material forming particular shapes with particular fillpercentages having particular patterns, this disclosure contemplates anysuitable electrodes made of any suitable conductive material forming anysuitable shapes with any suitable fill percentages having any suitablepatterns.

Where appropriate, the shapes of the electrodes (or other elements) of atouch sensor may constitute in whole or in part one or moremacro-features of the touch sensor. One or more characteristics of theimplementation of those shapes (such as, for example, the conductivematerials, fills, or patterns within the shapes) may constitute in wholeor in part one or more micro-features of the touch sensor. One or moremacro-features of a touch sensor may determine one or morecharacteristics of its functionality, and one or more micro-features ofthe touch sensor may determine one or more optical features of the touchsensor, such as transmittance, refraction, or reflection.

A mechanical stack may contain the substrate (or multiple substrates)and the conductive material forming the drive or sense electrodes oftouch sensor 10. As an example and not by way of limitation, themechanical stack may include a first layer of optically clear adhesive(OCA) beneath a cover panel. The cover panel may be clear and made of aresilient material suitable for repeated touching, such as for exampleglass, polycarbonate, or poly(methyl methacrylate) (PMMA). Thisdisclosure contemplates any suitable cover panel made of any suitablematerial. The first layer of OCA may be disposed between the cover paneland the substrate with the conductive material forming the drive orsense electrodes. The mechanical stack may also include a second layerof OCA and a dielectric layer (which may be made of PET or anothersuitable material, similar to the substrate with the conductive materialforming the drive or sense electrodes). As an alternative, whereappropriate, a thin coating of a dielectric material may be appliedinstead of the second layer of OCA and the dielectric layer. The secondlayer of OCA may be disposed between the substrate with the conductivematerial making up the drive or sense electrodes and the dielectriclayer, and the dielectric layer may be disposed between the second layerof OCA and an air gap to a display of a device including touch sensor 10and touch-sensor controller 12. As an example only and not by way oflimitation, the cover panel may have a thickness of approximately 1 mm;the first layer of OCA may have a thickness of approximately 0.05 mm;the substrate with the conductive material forming the drive or senseelectrodes may have a thickness of approximately 0.05 mm; the secondlayer of OCA may have a thickness of approximately 0.05 mm; and thedielectric layer may have a thickness of approximately 0.05 mm. Althoughthis disclosure describes a particular mechanical stack with aparticular number of particular layers made of particular materials andhaving particular thicknesses, this disclosure contemplates any suitablemechanical stack with any suitable number of any suitable layers made ofany suitable materials and having any suitable thicknesses. As anexample and not by way of limitation, in particular embodiments, a layerof adhesive or dielectric may replace the dielectric layer, second layerof OCA, and air gap described above, with there being no air gap to thedisplay.

One or more portions of the substrate of touch sensor 10 may be made ofpolyethylene terephthalate (PET) or another suitable material. Thisdisclosure contemplates any suitable substrate with any suitableportions made of any suitable material. In particular embodiments, thedrive or sense electrodes in touch sensor 10 may be made of ITO in wholeor in part. In particular embodiments, the drive or sense electrodes intouch sensor 10 may be made of fine lines of metal or other conductivematerial. As an example and not by way of limitation, one or moreportions of the conductive material may be copper or copper-based andhave a thickness of approximately 5 μm or less and a width ofapproximately 10 μm or less. As another example, one or more portions ofthe conductive material may be silver or silver-based and similarly havea thickness of approximately 5 μm or less and a width of approximately10 μm or less. This disclosure contemplates any suitable electrodes madeof any suitable material.

Touch sensor 10 may implement a capacitive form of touch sensing. In amutual-capacitance implementation, touch sensor 10 may include an arrayof drive and sense electrodes forming an array of capacitive nodes. Adrive electrode and a sense electrode may form a capacitive node. Thedrive and sense electrodes forming the capacitive node may come neareach other, but not make electrical contact with each other. Instead,the drive and sense electrodes may be capacitively coupled to each otheracross a space between them. A pulsed or alternating voltage applied tothe drive electrode (by touch-sensor controller 12) may induce a chargeon the sense electrode, and the amount of charge induced may besusceptible to external influence (such as a touch or the proximity ofan object). When an object touches or comes within proximity of thecapacitive node, a change in capacitance may occur at the capacitivenode and touch-sensor controller 12 may measure the change incapacitance. By measuring changes in capacitance throughout the array,touch-sensor controller 12 may determine the position of the touch orproximity within the touch-sensitive area(s) of touch sensor 10.

In a self-capacitance implementation, touch sensor 10 may include anarray of electrodes of a single type that may each form a capacitivenode. When an object touches or comes within proximity of the capacitivenode, a change in self-capacitance may occur at the capacitive node andcontroller 12 may measure the change in capacitance, for example, as achange in the amount of charge needed to raise the voltage at thecapacitive node by a pre-determined amount. As with a mutual-capacitanceimplementation, by measuring changes in capacitance throughout thearray, controller 12 may determine the position of the touch orproximity within the touch-sensitive area(s) of touch sensor 10. Thisdisclosure contemplates any suitable form of capacitive touch sensing,where appropriate.

In particular embodiments, one or more drive electrodes may togetherform a drive line running horizontally or vertically or in any suitableorientation. Similarly, one or more sense electrodes may together form asense line running horizontally or vertically or in any suitableorientation. In particular embodiments, drive lines may runsubstantially perpendicular to sense lines. Herein, reference to a driveline may encompass one or more drive electrodes making up the driveline, and vice versa, where appropriate. Similarly, reference to a senseline may encompass one or more sense electrodes making up the senseline, and vice versa, where appropriate.

Touch sensor 10 may have drive and sense electrodes disposed in apattern on one side of a single substrate. In such a configuration, apair of drive and sense electrodes capacitively coupled to each otheracross a space between them may form a capacitive node. For aself-capacitance implementation, electrodes of only a single type may bedisposed in a pattern on a single substrate. In addition or as analternative to having drive and sense electrodes disposed in a patternon one side of a single substrate, touch sensor 10 may have driveelectrodes disposed in a pattern on one side of a substrate and senseelectrodes disposed in a pattern on another side of the substrate.Moreover, touch sensor 10 may have drive electrodes disposed in apattern on one side of one substrate and sense electrodes disposed in apattern on one side of another substrate. In such configurations, anintersection of a drive electrode and a sense electrode may form acapacitive node. Such an intersection may be a location where the driveelectrode and the sense electrode “cross” or come nearest each other intheir respective planes. The drive and sense electrodes do not makeelectrical contact with each other—instead they are capacitively coupledto each other across a dielectric at the intersection. Although thisdisclosure describes particular configurations of particular electrodesforming particular nodes, this disclosure contemplates any suitableconfiguration of any suitable electrodes forming any suitable nodes.Moreover, this disclosure contemplates any suitable electrodes disposedon any suitable number of any suitable substrates in any suitablepatterns.

As described above, a change in capacitance at a capacitive node oftouch sensor 10 may indicate a touch or proximity input at the positionof the capacitive node. Touch-sensor controller 12 may detect andprocess the change in capacitance to determine the presence and locationof the touch or proximity input. Touch-sensor controller 12 may thencommunicate information about the touch or proximity input to one ormore other components (such one or more central processing units (CPUs))of a device that includes touch sensor 10 and touch-sensor controller12, which may respond to the touch or proximity input by initiating afunction of the device (or an application running on the device).Although this disclosure describes a particular touch-sensor controllerhaving particular functionality with respect to a particular device anda particular touch sensor, this disclosure contemplates any suitabletouch-sensor controller having any suitable functionality with respectto any suitable device and any suitable touch sensor.

Touch-sensor controller 12 may be one or more integrated circuits (ICs),such as for example general-purpose microprocessors, microcontrollers,programmable logic devices (PLDs) or programmable logic arrays (PLAs),application-specific ICs (ASICs). In particular embodiments,touch-sensor controller 12 comprises analog circuitry, digital logic,and digital non-volatile memory. In particular embodiments, touch-sensorcontroller 12 is disposed on a flexible printed circuit (FPC) bonded tothe substrate of touch sensor 10, as described below. The FPC may beactive or passive, where appropriate. In particular embodiments multipletouch-sensor controllers 12 are disposed on the FPC. Touch-sensorcontroller 12 may include a processor unit, a drive unit, a sense unit,and a storage unit. The drive unit may supply drive signals to the driveelectrodes of touch sensor 10. The sense unit may sense charge at thecapacitive nodes of touch sensor 10 and provide measurement signals tothe processor unit representing capacitances at the capacitive nodes.The processor unit may control the supply of drive signals to the driveelectrodes by the drive unit and process measurement signals from thesense unit to detect and process the presence and location of a touch orproximity input within the touch-sensitive area(s) of touch sensor 10.The processor unit may also track changes in the position of a touch orproximity input within the touch-sensitive area(s) of touch sensor 10.The storage unit may store programming for execution by the processorunit, including programming for controlling the drive unit to supplydrive signals to the drive electrodes, programming for processingmeasurement signals from the sense unit, and other suitable programming,where appropriate. Although this disclosure describes a particulartouch-sensor controller having a particular implementation withparticular components, this disclosure contemplates any suitabletouch-sensor controller having any suitable implementation with anysuitable components.

Tracks 14 of conductive material disposed on the substrate of touchsensor 10 may couple the drive or sense electrodes of touch sensor 10 toconnection pads 16, also disposed on the substrate of touch sensor 10.As described below, connection pads 16 facilitate coupling of tracks 14to touch-sensor controller 12. Tracks 14 may extend into or around(e.g., at the edges of) the touch-sensitive area(s) of touch sensor 10.Particular tracks 14 may provide drive connections for couplingtouch-sensor controller 12 to drive electrodes of touch sensor 10,through which the drive unit of touch-sensor controller 12 may supplydrive signals to the drive electrodes. Other tracks 14 may provide senseconnections for coupling touch-sensor controller 12 to sense electrodesof touch sensor 10, through which the sense unit of touch-sensorcontroller 12 may sense charge at the capacitive nodes of touch sensor10. Tracks 14 may be made of fine lines of metal or other conductivematerial. As an example and not by way of limitation, the conductivematerial of tracks 14 may be copper or copper-based and have a width ofapproximately 100 μm or less. As another example, the conductivematerial of tracks 14 may be silver or silver-based and have a width ofapproximately 100 μm or less. In particular embodiments, tracks 14 maybe made of ITO in whole or in part in addition or as an alternative tofine lines of metal or other conductive material. Although thisdisclosure describes particular tracks made of particular materials withparticular widths, this disclosure contemplates any suitable tracks madeof any suitable materials with any suitable widths. In addition totracks 14, touch sensor 10 may include one or more ground linesterminating at a ground connector (which may be a connection pad 16) atan edge of the substrate of touch sensor 10 (similar to tracks 14).

Connection pads 16 may be located along one or more edges of thesubstrate, outside the touch-sensitive area(s) of touch sensor 10. Asdescribed above, touch-sensor controller 12 may be on an FPC. Connectionpads 16 may be made of the same material as tracks 14 and may be bondedto the FPC using an anisotropic conductive film (ACF). Connection 18 mayinclude conductive lines on the FPC coupling touch-sensor controller 12to connection pads 16, in turn coupling touch-sensor controller 12 totracks 14 and to the drive or sense electrodes of touch sensor 10. Inanother embodiment, connection pads 16 may be connected to anelectro-mechanical connector (such as a zero insertion forcewire-to-board connector); in this embodiment, connection 18 may not needto include an FPC. This disclosure contemplates any suitable connection18 between touch-sensor controller 12 and touch sensor 10.

FIG. 2 illustrates an example exterior of an example active stylus 20.Active stylus 20 may include one or more components, such as buttons 30or sliders 32 and 34 integrated with an outer body 22. These externalcomponents may provide for interaction between active stylus 20 and auser or between a device and a user. As an example and not by way oflimitation, interactions may include communication between active stylus20 and a device, enabling or altering functionality of active stylus 20or a device, or providing feedback to or accepting input from one ormore users. The device may by any suitable device, such as, for exampleand without limitation, a desktop computer, laptop computer, tabletcomputer, personal digital assistant (PDA), smartphone, satellitenavigation device, portable media player, portable game console, kioskcomputer, point-of-sale device, or other suitable device. Although thisdisclosure provides specific examples of particular componentsconfigured to provide particular interactions, this disclosurecontemplates any suitable component configured to provide any suitableinteraction. Active stylus 20 may have any suitable dimensions withouter body 22 made of any suitable material or combination of materials,such as, for example and without limitation, plastic or metal. Inparticular embodiments, exterior components (e.g., 30 or 32) of activestylus 20 may interact with internal components or programming of activestylus 20 or may initiate one or more interactions with one or moredevices or other active styluses 20.

As described above, actuating one or more particular components mayinitiate an interaction between active stylus 20 and a user or betweenthe device and the user. Components of active stylus 20 may include oneor more buttons 30 or one or more sliders 32 and 34. As an example andnot by way of limitation, buttons 30 or sliders 32 and 34 may bemechanical or capacitive and may function as a roller, trackball, orwheel. As another example, one or more sliders 32 or 34 may function asa vertical slider 34 aligned along a longitudinal axis, while one ormore wheel sliders 32 may be aligned along the circumference of activestylus 20. In particular embodiments, capacitive sliders 32 and 34 orbuttons 30 may be implemented using one or more touch-sensitive areas.Touch-sensitive areas may have any suitable shape, dimensions, location,or be made from any suitable material. As an example and not by way oflimitation, sliders 32 and 34 or buttons 30 may be implemented usingareas of flexible mesh formed using lines of conductive material. Asanother example, sliders 32 and 34 or buttons 30 may be implementedusing a FPC.

Active stylus 20 may have one or more components configured to providefeedback to or accepting feedback from a user, such as, for example andwithout limitation, tactile, visual, or audio feedback. Active stylus 20may include one or more ridges or grooves 24 on its outer body 22.Ridges or grooves 24 may have any suitable dimensions, have any suitablespacing between ridges or grooves, or be located at any suitable area onouter body 22 of active stylus 20. As an example and not by way oflimitation, ridges 24 may enhance a user's grip on outer body 22 ofactive stylus 20 or provide tactile feedback to or accept tactile inputfrom a user. Active stylus 20 may include one or more audio components38 capable of transmitting and receiving audio signals. As an exampleand not by way of limitation, audio component 38 may contain amicrophone capable of recording or transmitting one or more users'voices. As another example, audio component 38 may provide an auditoryindication of a power status of active stylus 20. Active stylus 20 mayinclude one or more visual feedback components 36, such as alight-emitting diode (LED) indicator. As an example and not by way oflimitation, visual feedback component 36 may indicate a power status ofactive stylus 20 to the user.

One or more modified surface areas 40 may form one or more components onouter body 22 of active stylus 20. Properties of modified surface areas40 may be different than properties of the remaining surface of outerbody 22. As an example and not by way of limitation, modified surfacearea 40 may be modified to have a different texture, temperature, orelectromagnetic characteristic relative to the surface properties of theremainder of outer body 22. Modified surface area 40 may be capable ofdynamically altering its properties, for example by using hapticinterfaces or rendering techniques. A user may interact with modifiedsurface area 40 to provide any suitable functionally. For example andnot by way of limitation, dragging a finger across modified surface area40 may initiate an interaction, such as data transfer, between activestylus 20 and a device.

One or more components of active stylus 20 may be configured tocommunicate data between active stylus 20 and the device. For example,active stylus 20 may include one or more tips 26 or nibs. Tip 26 mayinclude one or more electrodes configured to communicate data betweenactive stylus 20 and one or more devices or other active styluses. Tip26 may be made of any suitable material, such as a conductive material,and have any suitable dimensions, such as, for example, a diameter of 1mm or less at its terminal end. Active stylus 20 may include one or moreports 28 located at any suitable location on outer body 22 of activestylus 20. Port 28 may be configured to transfer signals or informationbetween active stylus 20 and one or more devices or power sources. Port28 may transfer signals or information by any suitable technology, suchas, for example, by universal serial bus (USB) or Ethernet connections.Although this disclosure describes and illustrates a particularconfiguration of particular components with particular locations,dimensions, composition and functionality, this disclosure contemplatesany suitable configuration of suitable components with any suitablelocations, dimensions, composition, and functionality with respect toactive stylus 20.

FIG. 3 illustrates an example internal components of example activestylus 20. Active stylus 20 may include one or more internal components,such as a controller 50, sensors 42, memory 44, or power source 48. Inparticular embodiments, one or more internal components may beconfigured to provide for interaction between active stylus 20 and auser or between a device and a user. In other particular embodiments,one or more internal components, in conjunction with one or moreexternal components described above, may be configured to provideinteraction between active stylus 20 and a user or between a device anda user. As an example and not by way of limitation, interactions mayinclude communication between active stylus 20 and a device, enabling oraltering functionality of active stylus 20 or a device, or providingfeedback to or accepting input from one or more users.

Controller 50 may be a microcontroller or any other type of processorsuitable for controlling the operation of active stylus 20. Controller50 may be one or more ICs—such as, for example, general-purposemicroprocessors, microcontrollers, PLDs, PLAs, or ASICs. Controller 50may include a processor unit, a drive unit, a sense unit, and a storageunit. The drive unit may supply signals to electrodes of tip 26 throughcenter shaft 41. The drive unit may also supply signals to control ordrive sensors 42 or one or more external components of active stylus 20.The sense unit may sense signals received by electrodes of tip 26through center shaft 41 and provide measurement signals to the processorunit representing input from a device. The sense unit may also sensesignals generated by sensors 42 or one or more external components andprovide measurement signals to the processor unit representing inputfrom a user. The processor unit may control the supply of signals to theelectrodes of tip 26 and process measurement signals from the sense unitto detect and process input from the device. The processor unit may alsoprocess measurement signals from sensors 42 or one or more externalcomponents. The storage unit may store programming for execution by theprocessor unit, including programming for controlling the drive unit tosupply signals to the electrodes of tip 26, programming for processingmeasurement signals from the sense unit corresponding to input from thedevice, programming for processing measurement signals from sensors 42or external components to initiate a pre-determined function or gestureto be performed by active stylus 20 or the device, and other suitableprogramming, where appropriate. As an example and not by way oflimitation, programming executed by controller 50 may electronicallyfilter signals received from the sense unit. Although this disclosuredescribes a particular controller 50 having a particular implementationwith particular components, this disclosure contemplates any suitablecontroller having any suitable implementation with any suitablecomponents.

In particular embodiments, active stylus 20 may include one or moresensors 42, such as touch sensors, gyroscopes, accelerometers, contactsensors, or any other type of sensor that detect or measure data aboutthe environment in which active stylus 20 operates. Sensors 42 maydetect and measure one or more characteristic of active stylus 20, suchas acceleration or movement, orientation, contact, pressure on outerbody 22, force on tip 26, vibration, or any other suitablecharacteristic of active stylus 20. As an example and not by way oflimitation, sensors 42 may be implemented mechanically, electronically,or capacitively. As described above, data detected or measured bysensors 42 communicated to controller 50 may initiate a pre-determinedfunction or gesture to be performed by active stylus 20 or the device.In particular embodiments, data detected or received by sensors 42 maybe stored in memory 44. Memory 44 may be any form of memory suitable forstoring data in active stylus 20. In other particular embodiments,controller 50 may access data stored in memory 44. As an example and notby way of limitation, memory 44 may store programming for execution bythe processor unit of controller 50. As another example, data measuredby sensors 42 may be processed by controller 50 and stored in memory 44.

Power source 48 may be any type of stored-energy source, includingelectrical or chemical-energy sources, suitable for powering theoperation of active stylus 20. In particular embodiments, power source48 may be charged by energy from a user or device. As an example and notby way of limitation, power source 48 may be a rechargeable battery thatmay be charged by motion induced on active stylus 20. In otherparticular embodiments, power source 48 of active stylus 20 may providepower to or receive power from the device. As an example and not by wayof limitation, power may be inductively transferred between power source48 and a power source of the device.

FIG. 4 illustrates an example active stylus 20 with an example device52. Device 52 may have a display (not shown) and a touch sensor with atouch-sensitive area 54. Device 52 display may be a liquid crystaldisplay (LCD), a LED display, a LED-backlight LCD, or other suitabledisplay and may be visible though a cover panel and substrate (and thedrive and sense electrodes of the touch sensor disposed on it) of device52. Although this disclosure describes a particular device display andparticular display types, this disclosure contemplates any suitabledevice display and any suitable display types.

Device 52 electronics may provide the functionality of device 52. Asexample and not by way of limitation, device 52 electronics may includecircuitry or other electronics for wireless communication to or fromdevice 52, execute programming on device 52, generating graphical orother user interfaces (UIs) for device 52 display to display to a user,managing power to device 52 from a battery or other power source, takingstill pictures, recording video, other suitable functionality, or anysuitable combination of these. Although this disclosure describesparticular device electronics providing particular functionality of aparticular device, this disclosure contemplates any suitable deviceelectronics providing any suitable functionality of any suitable device.

In particular embodiments, active stylus 20 and device 52 may besynchronized prior to communication of data between active stylus 20 anddevice 52. As an example and not by way of limitation, active stylus 20may be synchronized to device through a pre-determined bit sequencetransmitted by the touch sensor of device 52. As another example, activestylus 20 may be synchronized to device by processing the drive signaltransmitted by drive electrodes of the touch sensor of device 52. Activestylus 20 may interact or communicate with device 52 when active stylus20 is brought in contact with or in proximity to touch-sensitive area 54of the touch sensor of device 52. In particular embodiments, interactionbetween active stylus 20 and device 52 may be capacitive or inductive.As an example and not by way of limitation, when active stylus 20 isbrought in contact with or in the proximity of touch-sensitive area 54of device 52, signals generated by active stylus 20 may influencecapacitive nodes of touch-sensitive area of device 52 or vice versa. Asanother example, a power source of active stylus 20 may be inductivelycharged through the touch sensor of device 52, or vice versa. Althoughthis disclosure describes particular interactions and communicationsbetween active stylus 20 and device 52, this disclosure contemplates anysuitable interactions and communications through any suitable means,such as mechanical forces, current, voltage, or electromagnetic fields.

In particular embodiments, measurement signal from the sensors of activestylus 20 may initiate, provide for, or terminate interactions betweenactive stylus 20 and one or more devices 52 or one or more users, asdescribed above. Interaction between active stylus 20 and device 52 mayoccur when active stylus 20 is contacting or in proximity to device 52.As an example and not by way of limitation, a user may perform a gestureor sequence of gestures, such as shaking or inverting active stylus 20,whilst active stylus 20 is hovering above touch-sensitive area 54 ofdevice 52. Active stylus may interact with device 52 based on thegesture performed with active stylus 20 to initiate a pre-determinedfunction, such as authenticating a user associated with active stylus 20or device 52. Although this disclosure describes particular movementsproviding particular types of interactions between active stylus 20 anddevice 52, this disclosure contemplates any suitable movementinfluencing any suitable interaction in any suitable way.

FIG. 5 illustrates example power management systems and power sourcesfor a touch sensor system. Power management systems and power sourcesmay be associated with components of the touch-sensor system, such asactive styluses, touch-sensitive devices, and the components associatedwith active styluses and touch-sensitive devices. Active stylus 20 mayhave one or more power sources 48. Likewise, touch-sensitive device 52may have one or more power sources 58. Power sources 48 and 58 maycommunicate with controllers 50 and 12, respectively. In particularembodiments, the communication is controlled or monitored by one or moregraphical user interfaces operating on any suitable active stylus ordevice. Power sources 48 and 58 may store, receive, transmit, or produceelectromagnetic energy suitable for use by a touch sensor system orassociated components. In particular embodiments, electromagnetic energyis received or transmitted by any suitable method such as wiring, directphysical contact, induction, temperature gradients, piezoelectricmaterials, mechanical methods, electromagnetic radiation, or anysuitable combination thereof. Power sources 48 and 58 may include anysuitable component that delivers, receives, produces, or modifiesenergy, such as a transformer. Power sources 48 and 58 may convert anykind of electromagnetic energy stored, produced, received, ortransmitted to any other kind of electromagnetic energy suitable for useby a touch sensor system and its associated components. Electromagneticenergy may be in any suitable form, such as electric fields, magneticfields, static configurations of electric charge, and electric currents.

Power source 48 may be external or internal to active stylus 20, andpower source 58 may be external or internal to touch-sensitive device52. In particular embodiments, an internal power source is a battery ora capacitor. In particular embodiments, an external power source is awall outlet or another device, such as a computer. A power sourceinternal to one active stylus or device may be external to anotheractive stylus or device. As an example of a particular embodiment, powersource 58 is internal to touch-sensitive device 52, while also servingas an external power source 48 for active stylus 20. While thisdisclosure describes specific examples of particular embodiments ofpower sources 48 and 58, this disclosure contemplates any suitable powersources 48 and 58 delivering, receiving, storing or producing anysuitable kind of electromagnetic energy by any suitable method to orfrom any suitable sources or destinations.

Active stylus 20 may have one or more power management systems 60.Likewise, touch-sensitive device 52 may have one or more powermanagement systems 56. Power management systems 60 and 56 maycommunicate with controllers 50 and 12, respectively. In particularembodiments, the communication is controlled or monitored by a graphicaluser interface operating on an active stylus or device. Power managementsystems 60 and 56 may control, modify, or record the receipt,production, or transfer of electromagnetic energy suitable for use by atouch sensor system or its associated components. In particularembodiments, power management systems 60 and 56 allocate to one or morecomponents associated with a touch sensor system electromagnetic energyexisting on or incoming to one or more components associated with thetouch sensor system. In particular embodiments, power management systems60 and 56 use criteria, such as metrics, to initiate, allocate, andterminate the allocation of energy between one or more components of atouch sensor system. In particular embodiments, power management systems60 and 56 allocate a particular amount of power to one or morecomponents associated with a touch sensor system, and are capable ofallocating different amounts of power to particular components atdifferent times. As an example, a power management system 60 determinespower modes of an active stylus. A power mode describes the amount ofpower sent to one or more components associated with an active stylus.The power management system 60 may transition the active stylus betweenpower modes based at least in part on input from a user or an activestylus or device. A graphical user interface may allow a user to controlor monitor the power modes of an active stylus and the method orcriteria used to transition between them.

FIG. 6 illustrates a particular embodiment of power modes for an activestylus and the methods of transitioning between them. In this example,an active stylus has three power modes: deep sleep 62, sleep 64, andactive 66. While this disclosure provide specific examples of particularembodiments illustrating the number of power modes, specific componentspowered in a particular way in a power mode, and the methods ofswitching between power modes, this disclosure contemplates any suitablenumber of power modes powering any suitable components in any suitableway. This disclosure further contemplates transitioning between any twopower modes in any suitable way.

In power mode deep sleep 62, a substantial number of components receiveno power or operate in low power modes. As an example, a receiver thatreceives signals from a touch-sensitive device and a transmitter thattransmits signals to a touch-sensitive device are powered off when theactive stylus is in deep sleep 62, a MCU operates in a low-power state,and one or more sensors are off or operating in a low-power state. Whilethis disclosure contemplates particular examples of power mode deepsleep 62, this disclosure contemplates any suitable components poweredin any suitable way in deep sleep 62.

In power mode sleep 64, some components receive no power or low power asin deep sleep 62 while at least one component is receiving more powerthan in deep sleep 62. As an example, an MCU receives 10 to 30 timesmore power in sleep 64 than in deep sleep 62. As another example, areceiver is powered on at least periodically while a transmitter ispowered off. As another example, one or more sensors are powered on insleep 64 that were powered off in deep sleep 62. While this disclosurecontemplates particular examples of power mode sleep 64, this disclosurecontemplates any suitable components powered in any suitable way insleep 64.

One or more components that are powered off or in a low-power state insleep 64 are powered on or in a full-power state in power mode active66. As an example, a receiver and a transmitter are powered on at leastperiodically, and an MCU operates in full-power mode. As anotherexample, one or more sensors are powered on in active 66 that werepowered off in sleep 64. While this disclosure contemplates particularembodiments of power mode active 66, this disclosure contemplates anysuitable components powered in any suitable way in active 66.

In particular embodiments, a power management system may transitionbetween any two power modes based on any suitable criteria, such asinput from a user, detection or loss of a signal, or communicationbetween the active stylus and a device, such as a computer ortouch-sensitive device. As an example, an active stylus transitions 68from deep sleep 62 to sleep 64 when a user operates a button or switchor places pressure in a specific way on the active stylus. As anotherexample, an active stylus transitions 70 from sleep 64 to deep sleep 62when the receiver in the active stylus does not detect one or moresignals from a touch-sensitive device for a predetermined amount oftime. As another example, an active stylus transitions 72 from sleep 64to active 66 when the active stylus detects the presence of atouch-sensitive device or particular functionality demanded by a user,such as a gesture performed by the active stylus. As another example, anactive stylus transitions 74 from active 66 to sleep 64 when the activestylus does not communicate with a touch-sensitive device for apredetermined period of time. As another example, an active stylustransitions 76 from active 66 to deep sleep 62 when a user operates aswitch or tethers the active stylus to a touch-sensitive device. Asanother example, an active stylus transitions 78 from deep sleep 62 toactive 66 when a user performs a particular gesture associated with thetransition, such as shaking the active stylus. The functionalityassociated with a particular button push, switch operation, gestureperformed, signal detected or lost, and predetermined amount of time maybe set by a user, an active stylus, or a touch-sensitive device, and maybe different in different power modes. While this disclosure describesspecific examples of particular embodiments of transitions between anytwo power modes, this disclosure contemplates an active stylus switchingbetween any two power modes based on any suitable method or criteria.

FIG. 7 illustrates an example method for powering an active stylus in avariety of power modes. The method may begin at step 82, in which theactive stylus is powered off. Power toggle 84, such as a button press,puts the stylus in active mode 86, which powers a receiver, atransmitter, one or more sensors, and a high-voltage pump and puts theMCU in full-power mode, in which the MCU is ready to transmit signals.One or more sensors communicate with the MCU. At step 88, the MCU mayreceive an incoming signal, store it, and alter it. The MCU may transmitthe received signal to the active stylus tip at step 90. While in activemode 86, if no signal is received for a first predetermined amount oftime set by a user, active stylus, or device, timeout 92 occurs, whichputs the stylus in sleep mode 94 by powering down the transmitter,putting the MCU in a low-power mode, putting one or more sensors ininterrupt-only mode, and powering off any high-voltage components of theactive stylus. If a signal from one or more sensors interrupts 96 sleepmode 94, the active stylus returns to active mode 86. If no signal isreceived for a second predetermined amount of time set by a user, activestylus, or device, timeout 98 occurs, placing the stylus in deep sleepmode 100 by powering the receiver and transmitter off and putting theMCU to sleep. Deep sleep 100 may be interrupted 102 by signals from oneor more sensors, putting the stylus in sleep mode 94 or active mode 86.If deep sleep 100 is not interrupted by one or more sensors for a thirdpredetermined amount of time set by a user, active stylus, or devicetimeout 104 occurs, powering the active stylus off. Particularembodiments may repeat the steps of the method of FIG. 7 , whereappropriate. Moreover, although this disclosure describes andillustrates particular steps of the method of FIG. 7 as occurring in aparticular order, this disclosure contemplates any suitable steps of themethod of FIG. 7 occurring in any suitable order. Furthermore, althoughthis disclosure describes and illustrates particular components,devices, or systems carrying out particular steps of the method of FIG.7 , this disclosure contemplates any suitable combination of anysuitable components, devices, or systems carrying out any suitable stepsof the method of FIG. 7 .

In particular embodiments, in any power mode in which a component ispowered on a power management system may power the component on for onlya certain period of time. As an example, a power management system dutycycles one or more components in one or more power modes. FIG. 8illustrates an example of duty cycling a transmitter that transmitssignals from active stylus 20 to touch-sensitive device 52.

Touch sensitive area 54 contains drive lines 112 and sense lines 114.Touch-sensitive device 52 may periodically scan sense lines 114 or drivelines 112. For example, touch-sensitive device 52 may periodicallyprovide increased voltage to drive lines 112. Graph 118 illustrates anexample method touch-sensitive device 52 may use to scan drive lines112. Touch-sensitive device 52 begins scanning drive line xi at time tiand proceeds to scan drive lines linearly as a function of time,scanning drive line xn at time tn. Touch-sensitive device 52 scans thelast drive line xf at time tf, at which point it may repeat the process,starting once again at drive line xi. While this disclosure describes aspecific example of a particular embodiment used to periodically scandrive lines 112, this disclosure contemplates scanning drive lines 112in any suitable method in any suitable timeframe.

Graph 120 illustrates an example duty cycling of a transmitter of activestylus 20. At point 116, active stylus 20 is in the immediate proximityof drive line xn, which is being scanned by touch-sensitive device 52 attime tn as illustrated in graph 118. Active stylus 20 supplies thetransmitter with power Phigh during a window of time around tn. Thewindow of time may account for possible motion of active stylus 20.Outside of this window of time, active stylus 20 supplies thetransmitter with power Plow, for example powering the transmitter off.In particular embodiments, active stylus 20 may dynamically learn themethod and timing touch-sensitive device 52 uses to scan drive lines112. As an example, active stylus 20 initially supplies the transmitterwith power Phigh continuously and, as active stylus 20 learns the methodand timing touch-sensitive device 52 uses to scan drive lines, thewindow of time that the transmitter receives power Phigh is decreased toa suitable duration. As another example of a particular embodiment ofduty cycling, active stylus 20 periodically powers for a suitableduration a receiver that receives signals from drive lines 112 oftouch-sensitive device 52. While this disclosure describes specificexamples of a specific component being duty cycled between particularpower levels in a particular way during a particular window of time,this disclosure contemplates any suitable component being duty cycledbetween any suitable power levels in suitable way for any suitableperiod of time.

Herein, reference to a computer-readable non-transitory storage mediumincludes a semiconductor-based or other integrated circuit (IC) (such,as for example, a field-programmable gate array (FPGA) or anapplication-specific IC (ASIC)), a hard disk (HDD), a hybrid hard drive(HHD), an optical disc, an optical disc drive (ODD), a magneto-opticaldisc, a magneto-optical drive, a floppy disk, a floppy disk drive (FDD),magnetic tape, a holographic storage medium, a solid-state drive (SSD),a RAM-drive, a SECURE DIGITAL card, a SECURE DIGITAL drive, or anothersuitable computer-readable non-transitory storage medium or acombination of two or more of these, where appropriate. Acomputer-readable non-transitory storage medium may be volatile,non-volatile, or a combination of volatile and non-volatile, whereappropriate.

Herein, “or” is inclusive and not exclusive, unless expressly indicatedotherwise or indicated otherwise by context. Therefore, herein, “A or B”means “A, B, or both,” unless expressly indicated otherwise or indicatedotherwise by context. Moreover, “and” is both joint and several, unlessexpressly indicated otherwise or indicated otherwise by context.Therefore, herein, “A and B” means “A and B, jointly or severally,”unless expressly indicated otherwise or indicated otherwise by context.

This disclosure encompasses all changes, substitutions, variations,alterations, and modifications to the example embodiments herein that aperson having ordinary skill in the art would comprehend. Moreover,reference in the appended claims to an apparatus or system or acomponent of an apparatus or system being adapted to, arranged to,capable of, configured to, enabled to, operable to, or operative toperform a particular function encompasses that apparatus, system,component, whether or not it or that particular function is activated,turned on, or unlocked, as long as that apparatus, system, or componentis so adapted, arranged, capable, configured, enabled, operable, oroperative.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

The invention claimed is:
 1. A stylus, comprising: one or moreelectrodes; and one or more computer-readable non-transitory storagemedia embodying logic for transmitting signals wirelessly to a devicethrough a touch-sensor of the device; the stylus having: a first powermode in which components of the stylus for receiving signals from thedevice are powered off and components of the stylus for transmittingsignals to the device are powered off; a second power mode in which thecomponents of the stylus for receiving drive signals transmitted bydrive electrodes of the device and used by the stylus to detect thedevice are periodically switched between a powered on state and apowered off state at a first duty cycle and the components of the stylusfor transmitting signals to the device are powered off; and a thirdpower mode in which the components of the stylus for receiving the drivesignals transmitted by the drive electrodes of the device are powered onat a second duty cycle that is higher than the first duty cycle and thecomponents of the stylus for transmitting stylus signals to the deviceare powered on to transmit the stylus signals; wherein the stylus in thesecond mode, in response to detecting the drive signals transmitted bythe drive electrodes of the device, transitions from the second mode tothe third mode.
 2. The stylus of claim 1, wherein the drive signalincludes a pre-determined bit sequence, and the stylus synchronizes withthe device using the pre-determined bit sequence.
 3. The stylus of claim1, wherein the stylus, in operation, transitions from one of the first,second, and third power modes to another one of the first, second, andthird power modes based at least in part on an input from a user of thestylus.
 4. The stylus of claim 3, wherein the input is a gestureperformed with the stylus.
 5. The stylus of claim 1, wherein the stylus,in operation, transitions from one of the first, second, and third powermodes to another one of the first, second, and third power modes basedat least in part on detection of, or loss of, a signal generated by thedevice.
 6. The stylus of claim 1, wherein, in the third power mode, thecomponents of the stylus for transmitting signals to the device arepowered on during windows of time when drive lines of the touch-sensorwithin proximity of the stylus are scanned.
 7. The stylus of claim 6,wherein, in the third power mode, the components of the stylus fortransmitting signals to the device are powered on during increasinglyshorter periods of time until the periods of time are greater than butwithin a pre-determined range of all windows of time when any of thedrive lines of the touch sensor are scanned.
 8. The stylus of claim 7,wherein, in the third power mode, the pre-determined range issufficiently greater than the windows of time when drive lines of thetouch-sensor within proximity of the stylus are scanned so that, if thestylus moves relative to the device, the components of the stylus fortransmitting signals to the device are powered on during windows of timewhen drive lines of the touch-sensor within the new proximity of thestylus are scanned.
 9. A method implemented by a stylus, the methodcomprising: transmitting signals wirelessly to a device through atouch-sensor of the device; transitioning the stylus from one of a firstpower mode, a second power mode, and a third power mode to another oneof the first power mode, the second power mode, and the third powermode, wherein, in the first power mode, components of the stylus forreceiving signals from the device are powered off and components of thestylus for transmitting signals to the device are powered off; in thesecond power mode, the components of the stylus for receiving drivesignals transmitted by drive electrodes of the device and used by thestylus to detect the device are periodically switched between a poweredon state and a powered off state at a first duty cycle and thecomponents of the stylus for transmitting signals to the device arepowered off; and in the third power mode, the components of the stylusfor receiving the drive signals transmitted by the drive electrodes ofthe device are powered on at a second duty cycle that is higher than thefirst duty cycle and the components of the stylus for transmittingstylus signals to the device are powered on to transmit the stylussignals; and transitioning the stylus from the second mode to the thirdmode in response to detecting the drive signals transmitted by the driveelectrodes of the device.
 10. The method of claim 9, wherein the stylusis transitioned from one of the first, second, and third power modes toanother one of the first, second, and third power modes based at leastin part on an input from a user of the stylus.
 11. The method of claim10, wherein the input is a gesture performed with the stylus.
 12. Themethod of claim 9, wherein the stylus is transitioned from one of thefirst, second, and third power modes to another one of the first,second, and third power modes based at least in part on detection of, orloss of, a signal generated by the device.
 13. The method of claim 9,wherein, in the third power mode, the components of the stylus fortransmitting signals to the device are powered on during windows of timewhen drive lines of the touch-sensor within proximity of the stylus arescanned.
 14. The method of claim 13, wherein, in the third power mode,the components of the stylus for transmitting signals to the device arepowered on during increasingly shorter periods of time until the periodsof time are greater than but within a pre-determined range of allwindows of time when any of the drive lines of the touch sensor arescanned.
 15. The method of claim 14, wherein, in the third power mode,the pre-determined range is sufficiently greater than the windows oftime when drive lines of the touch-sensor within proximity of the stylusare scanned so that, if the stylus moves relative to the device, thecomponents of the stylus for transmitting signals to the device arepowered on during windows of time when drive lines of the touch-sensorwithin the new proximity of the stylus are scanned.
 16. An integratedcircuit configured to control a stylus, comprising: one or morecomputer-readable non-transitory storage media; and logic embodied inthe one or more computer-readable non-transitory storage media fortransmitting signals wirelessly from the stylus to a device through atouch-sensor of the device; the stylus having: a first power mode inwhich components of the stylus for receiving signals from the device arepowered off and components of the stylus for transmitting signals to thedevice are powered off; a second power mode in which the components ofthe stylus for receiving drive signals transmitted by drive electrodesof the device and used by the stylus to detect the device areperiodically switched between a powered on state and a powered off stateat a first duty cycle and the components of the stylus for transmittingsignals to the device are powered off; and a third power mode in whichthe components of the stylus for receiving the drive signals transmittedby the drive electrodes of the device are powered on at a second dutycycle that is higher than the first duty cycle and the components of thestylus for transmitting stylus signals to the device are powered on totransmit the stylus signals; wherein the logic, in response to detectingthe drive signals transmitted by the drive electrodes of the device,transitions the stylus from the second mode to the third mode.
 17. Theintegrated circuit of claim 16, wherein the drive signal includes apre-determined bit sequence, and the logic synchronizes the stylus withthe device using the pre-determined bit sequence.
 18. The integratedcircuit of claim 16, wherein the logic, in operation, transitions thestylus from one of the first, second, and third power modes to anotherone of the first, second, and third power modes based at least in parton an input from a user of the stylus.
 19. The integrated circuit ofclaim 18, wherein the input is a gesture performed with the stylus. 20.The integrated circuit of claim 16, wherein the logic, in operation,transitions the stylus from one of the first, second, and third powermodes to another one of the first, second, and third power modes basedat least in part on detection of, or loss of, a signal generated by thedevice.